Explanatory notes for Measuring Unit Floor Area (TCI Base Table)

Unit Floor Area

Unit size, in square metres shown on the TCI base table, relates to the total permitted floor area of the unit. Determining the unit size is a core element of calculating applicable grant and must be given due consideration. The unit size will vary depending on the type of housing to be provided and the needs group. Association must refer and apply the Design Standards criteria applicable to various needs groups.

Associations are responsible for ensuring that the measurement criteria have been correctly applied to properties presented for consideration and takes account of room shape and features as well as floor area. This includes the accurate measurement and designation of unit size for Off-the-Shelf and Existing Satisfactory Purchases according to Departmental requirements. Correct identification of Unit Size is essential to ensure accurate assessment of applicable grant for Associations’ financial viability assessments of schemes and will help avoid unnecessary delay at scheme submission stage.

TCI for larger units, where the total floor area exceeds 120m², will be calculated by taking the appropriate cost for a unit of 115-120m² PLUS (for each additional 5m² or part thereof) the difference between the cost of a unit of 110-115m² and a unit of 115-120m².

The base TCI is calculated differently for self-contained and shared accommodation. Associations should carefully follow the guidance below.

Self-Contained Accommodation

Self-contained units provide each household, defined as a tenancy, with all their basic facilities behind their own lockable front door. For self-contained units the base TCI is determined by its total permissible floor area. The dwelling floor area is determined by the area of each unit for the private use of a single household.

Measuring permissible floor area (self-contained)

The total floor area of self-contained accommodation - is measured to the internal faces of the main containing walls on each floor of the accommodation and includes the space, on plan, taken up by private staircases, partitions, internal walls (but not ‘party’ or similar walls), chimney breasts, flues and heating appliances. It includes the area of tenants’ storage space, including any externally accessed storage within the main containing walls.

Space Exclusions – Self-Contained Units

All floor area falling within the below criteria must be deducted from the total floor area:

Any space where the height to the ceiling is less than 1.5 m (e.g., areas in rooms with sloping ceilings, external dustbin enclosures)
Any porch, covered way, etc, open to air; all balconies (private, escape and access) and decks
Non-habitable basements and attics, conservatories, sheds etc
All space for purposes other than housing (i.e., garages, commercial premises, etc)
Communal areas or any facilities shared by 2 or more households must be excluded

The remaining area, after deduction of excluded spaces, is the permitted area to be used in selecting the appropriate unit size applicable to the property.

Shared Accommodation

This term applies to accommodation for two or more people in which households with different tenancies/licences share facilities, i.e., bathroom, kitchen, etc. There may be a number of shared units within the same scheme. (Note: The base TCI for shared accommodation must be calculated separately to any self-contained accommodation in the scheme).

Measuring permissible floor area (shared)

For shared units the base TCI per person is determined by the total floor area of each shared unit divided by the number of resident’s bed spaces sharing that unit including any residential staff bed space and any guest-room bed-space contained within the shared unit.

The total floor area of shared accommodation is measured to the internal faces of the main containing walls on each floor of the unit and includes all space for shared facilities for services and the space, on plan, taken up by staircases, partitions, internal walls (but not ‘party’ or similar walls), chimney breasts, flues and heating appliances. It includes the area of residents’ storage space, (including any externally accessed storage within the main containing walls) except where a non-habitable basement or attic is used exclusively as storage space.

Space Exclusions – Shared Units